i rent it for almost 3 weeks. it's work better than single elec pump becoz:
1. pressure become steady,
2. less noisy,
3. easiler to remove the pumping cap from the plastic bottle connector,
4. the pump action on left and right at the same time, no delay action,
5. save 1/2 time for pumping,
6. increase amount of milk during each pumping work.